Field of the Invention
The present invention relates to a liquid ejection head used in a liquid ejection apparatus and a liquid ejection apparatus.
Description of the Related Art
A liquid ejection apparatus includes a liquid ejection head that ejects a liquid. The liquid ejection head includes an ejection element substrate that includes a plurality of ejection openings arranged to eject a liquid therefrom, a support member that supports and fixes the ejection element substrate, and an electrical wiring substrate that transmits an ejection signal to the ejection element substrate. The periphery of the ejection element substrate is sealed by a sealant. Since the periphery of the ejection element substrate is sealed, the corrosion of the electrical wiring substrate or the non-protected end surface of the ejection element substrate is suppressed.
Further, lead terminals connected to bumps provided on the ejection element substrate and the electrical wiring substrate are also sealed by a sealant. By the sealing operation, the corrosion of the lead terminals caused by the liquid is prevented.
In order to select a material having a high adhesion property with respect to a plurality of members as the sealant used in this way, a material having a large internal stress or linear expansion coefficient in a hardened state needs to be selected. Accordingly, there is a case in which the sealant having a large internal stress or linear expansion coefficient in a hardened state may damage the ejection element substrate due to the expansion/contraction state of the sealant, the hardened shrinkage of the sealant, and the swelling of the sealant caused by an ink in accordance with a change in temperature in a manufacturing process and a change in temperature in a product usage environment.
In some cases, the amount of the sealant is decreased in order to prevent the damage of the ejection element substrate. If the amount of the sealant is decreased, a wiper may be abraded by the edge of the ejection element substrate when a surface provided with the ejection opening of the liquid ejection head is cleaned by the wiper. As a result, the cleaning operation is not sufficiently performed at the abraded portion and hence the ejection operation is influenced.
Japanese Patent Laid-Open No. 2008-23962 discloses a configuration in which a block is provided in a space between an ejection element substrate and a second support member or the block is integrated with the second support member. Accordingly, the amount of the sealant is decreased and the expansion/contraction amount of the sealant is decreased. As a result, the wiper is not abraded while the damage of the ejection element substrate is prevented.
However, Japanese Patent Laid-Open No. 2008-23962 does not disclose a technique of sealing the second support member and the electrical wiring substrate. Further, it is difficult to apply a sealant by a needle even when the second support member and the electrical wiring substrate are sealed.
Therefore, a method of supplying a sealant to a sealing portion by a capillary phenomenon is considered. However, since the second support member and the electrical wiring substrate come into close contact with each other, the sealant hardly enters therebetween. Further, since the size of the gap is not taken into consideration, a sealant is not easily supplied to a boundary surface between both members by the capillary phenomenon. As a result, there is a concern that the sealing operation is not sufficiently performed and the insulation property of the electrical wiring substrate is degraded.